The present invention relates generally to an apparatus for dispensing individual plastic fasteners from fastener stock and, more particularly, to a needle lock for an apparatus for dispensing individual plastic fasteners from fastener stock.
Plastic fasteners of the type having a cross-bar at one end, a paddle at the other end and a thin filament or cross-link connecting the two ends are well known in the art and are widely used in commerce to attach labels, price tags or other items to articles in a manner which minimizes the risk of inadvertent detachment therefrom. Typically, such plastic fasteners are manufactured in the form of a supply of fastener stock, the fastener stock being produced by molding or stamping from flexible plastic materials, such as nylon, polyethylene, and polypropylene.
In one well known type of fastener stock, the cross bar end of each fastener is connected to a runner bar to form a clip of fasteners. In another known type of fastener stock, often referred to simply as ladder stock, a pair of elongated side members are interconnected by a plurality of cross links or filaments. One of the side members is shaped to define a plurality of cross bars which are joined together by short severable connectors, the connectors being defined by indentations or notches formed along the side member. The other side member is shaped to define either a plurality of paddles or cross bars which are similarly joined together by short severable connectors.
The dispensing of individual fasteners from fastener stock is often accomplished with an apparatus commonly referred to as a tagger gun. A tagger gun is a hand held trigger operated device which is constructed to accept fastener stock and dispense individual fasteners into one or more desired articles (i.e., items to be tagged).
A tagger gun commonly includes a gun-shaped housing and a needle which is slidably disposed within a cylindrical needle receiving bore formed in the front of the housing, the needle including a sharpened tip. Tagger guns also typically include an indexing mechanism for feeding the cross bar end of an individual fastener into the rear end of the hollow needle and an ejection mechanism for pushing the cross bar end of the individual fastener that has been fed into the hollow needle out through its sharpened tip.
In use, an operator can use a tagger gun of the type described above to attach an individual plastic fastener to one or more desired objects in the following manner. Specifically, the operator first loads the supply of fastener stock into the tagger gun. With the fastener stock loaded, the operator inserts the sharpened tip of the needle through the items to be tagged. The operator then activates the trigger of the tagger gun which, in turn, first feeds the cross bar end of an individual fastener into alignment with the rear end of the hollow needle and then urges the cross bar end of the individual fastener out through the sharpened tip of the hollow needle. Once the cross bar end of the individual fastener exits the sharpened tip of the hollow needle, the cross bar end and the paddle of the individual fastener are disposed on opposite sides of the tagged items, thereby completing the tagging process. Withdrawing the tagger gun away from the dispensed fastener causes the dispensed fastener to separate from the remainder of the fastener stock loaded into the tagger gun. The process can be repeated as deemed necessary by the operator. It should be noted that feeding and ejection mechanisms of some tagger guns are manually operated while the feeding and ejection mechanisms of some other tagger guns are powered by an electric motor or a pneumatic device.
Tagger guns have been developed and are in use with both of the above described types of fastener stock.
For example, in U.S. Pat. No. 4,456,123 to D. B. Russell, which is incorporated herein by reference, there is disclosed an apparatus for dispensing fasteners which is manufactured and sold by AVERY DENNISON CORPORATION(copyright) of Pasadena, Calif. as the SYSTEM 1000(copyright) SWIFTACHER(copyright) Tool. The apparatus can be used to store, feed and dispense fastener stock of the type which includes a plurality of connected fasteners, each fastener comprising a flexible filament and a transversely disposed end-bar at one end, end-bars of adjacent fasteners being joined end-to-end by severable connectors at a portion of their peripheries. The apparatus comprises a hollow casing and a dispensing needle mounted to the casing, the needle having a longitudinal bore for slidably receiving the end-bar and a slot communicating with the longitudinal bore slidably receiving the filament. The apparatus also comprises means for advancing a fastener from a first position remote from the needle bore to a second position adjacent the rear end of the bore with the end-bar transversely disposed to the longitudinal axis of the bore, means for aligning the end-bar with the bore and means for dispensing the end-bar through the bore.
Other types of tagger guns are disclosed in U.S. Pat. Nos. 5,772,073, 5,683,025, 5,024,365, 4,533,076, 4,456,161, 4,121,487, and 4,456,123.
Tagger guns of the type described above typically include a conventional needle which comprises a stem portion and a base portion. The stem portion, which may be made from stamped and rolled metal, is a generally cylindrical member terminating at one end in a sharp tip designed for insertion through a garment or like object. The stem portion also has a slotted bore which extends substantially longitudinally therethrough. The base portion may be made of a plastic that has been insert-molded onto that end of the stem portion that is distal to the tip. (Alternatively, the stem portion and the base portion may be a unitary structure made of metal or another suitable material.) The base portion is provided with a slotted longitudinal bore that is aligned with the bore of the stem portion and is also provided with a scalloped-shaped recess on its outer surface. The bores of the stem portion and the base portion of the needle are appropriately dimensioned so that the cross-bar of a fastener may be inserted thereinto from the rear of the base portion, traverse the length of the needle through the bore of the stem portion and then exit the needle through the sharpened tip. The slots of the stem portion and the base portion are appropriately dimensioned to permit the filament of the fastener to extend therethrough while its associated cross-bar is disposed within the needle.
It should be noted that, during the life of a tagger gun, the needle may require replacement. For example, the needle of a tagger gun may break, thereby precluding further use, which is highly undesirable. As another example, the sharpened tip of a needle may become dulled after considerable use which, in turn, can cause the needle to potentially rip or tear future items to be tagged, which is highly undesirable.
Accordingly, tagger guns are often constructed to allow for its needle to be removed and replaced, as deemed necessary. Specifically, tagger guns are commonly constructed so that the needle may be slidably disposed within a tagger gun housing. The needle, in turn, can then be fixedly secured (i.e., locked in place) within the tagger gun housing using a needle lock.
Needle locks (also commonly referred to as locking pins) are well known and widely used in the art to releasably lock a hollow needle in place within a tagger gun housing. A needle lock is typically slidably disposed within a needle lock bore formed into a side of the tagger gun housing, the longitudinal axis of the needle lock extending at approximately a right angle relative to the longitudinal axis of the hollow needle.
A needle lock typically comprises an elongated, generally cylindrical locking post having a first end and a second end. A scallop-shaped recess is formed on the outer surface of the locking post at about its midpoint. An enlarged button-shaped head is formed onto the first end of the locking post. The head is preferably constructed to facilitate rotation of the needle lock by the user. As an example, a slot may be formed onto the free end of the head which enables the user rotate the needle lock using a screwdriver or other similar instrument. As another example, an elongated handle may be formed onto the free end of the head which enables the user to rotate the needle lock with his/her fingers.
A needle lock of the type described above is typically disposed within the housing of a tagger gun in the following manner. The second end of the needle lock is inserted into a needle lock bore formed into the housing of the tagger gun. The needle lock is inwardly advanced into the needle lock bore until the enlarged, button-shaped head of the needle lock abuts against the tagger gun housing, thereby precluding further inward displacement.
It should be noted that the scalloped-shaped recess formed on the needle lock is appropriately dimensioned to receive the base portion of the hollow needle, and the scalloped-shaped recess formed on the base portion of the hollow needle is appropriately dimensioned to receive the needle lock. As such, the needle lock can be rotated between a first position in which the needle lock secures the needle in place within the tagger gun housing (said position being referred to herein simply as the locked position) and a second position in which the needle lock allows the needle to freely slide in and out of the needle receiving bore in the tagger gun housing (said position being referred to herein simply as the unlocked position). Specifically, with the needle lock disposed in its locked position, the locking post of the needle lock aligns within the scalloped-shaped recess formed in the needle which, in turn, causes the needle lock to lockably engage the base portion of the needle and preclude longitudinal displacement. To the contrary, with the needle lock disposed in its unlocked position, the locking post of the needle lock is rotated out from the scalloped-shaped recess in the needle which, in turn, causes the needle lock to disengage from the base portion of the needle, thereby enabling the needle to be axially displaced within the needle receiving bore formed in the tagger gun housing.
Although well-known and widely used in commerce, locking pins of the type described above suffer from a notable drawback. Specifically, locking pins of the type described above are not permanently retained within the tagger gun housing. Rather, locking pins of the type described above are removably mounted into the tagger gun housing. As such, it has been found that conventional needle locks are often inadvertently removed from the housing and subsequently lost. As can be appreciated, without the needle lock, there is no means for fixedly securing the needle within the housing of the tagger gun, thereby rendering the tagger gun incapable of being used, which is highly undesirable.
It is an object of the present invention to provide a new and improved apparatus for dispensing individual plastic fasteners from fastener stock.
It is another object of the present invention to provide an apparatus of the type described above which includes a gun-shaped housing and a hollow, slotted needle which is removably mounted within a cylindrical needle receiving bore.
It is yet another object of the present invention to provide an apparatus of the type described above which includes a needle lock for selectively locking said needle in place within the needle receiving bore.
It is still another object of the present invention to provide an apparatus of the type described above in which the needle lock is permanently mounted into a needle lock receiving bore.
It is another object of the present invention to provide an apparatus of the type described above which has a limited number of parts, which is easy to use, and which is inexpensive to manufacture.
Accordingly, as one feature of the present invention, there is provided an apparatus for dispensing plastic fasteners, each plastic fastener comprising a cross-bar end, said apparatus comprising a casing, a needle assembly disposed at least partially within said casing, said needle assembly comprising, a needle carrier slidably disposed at least partially within said casing, said needle carrier being shaped to include a needle receiving bore and a needle lock receiving bore, a needle removably disposed into the needle receiving bore in said needle carrier, and a needle lock for selectively locking said needle within the needle receiving bore, said needle lock being snap-mounted into the needle lock receiving bore in said needle carrier, said needle lock being adapted to engage said needle carrier upon the application of a withdrawal force on said needle lock from said needle carrier, and a mechanism for pushing the cross bar end of a plastic fastener through said needle.
As another feature of the present invention, there is provided a needle assembly for an apparatus for dispensing plastic fasteners, said needle assembly comprising a needle carrier shaped to include a needle receiving bore and a needle lock receiving bore, a needle removably disposed into the needle receiving bore in said needle carrier, and a needle lock for selectively locking said needle within the needle receiving bore of said needle carrier, said needle lock being snap-mounted into the needle lock receiving bore in said needle carrier, said needle lock being adapted to engage said needle carrier upon the application of a withdrawal force on said needle lock from said needle carrier.
As another feature of the present invention, there is provided a needle lock for selectively locking a needle within a needle receiving bore, said needle lock comprising a locking post having a first end and a second end, the first end of said locking post being shaped to include a slot, and an enlarged head formed onto the second end of said locking post.
Various other features and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration, various embodiments for practicing the invention. The embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.